PROJECT SUMMARY/ABSTRACT Our multidisciplinary translational research team has generated and developed a humanized monoclonal antibody (mAb) with a high affinity (Kd = 4 nM) for cocaine and specificity over the inactive metabolites of cocaine. This recombinant mAb is a unique new molecular entity with a preclinical designation of h2E2. We have shown that h2E2 dramatically lowers brain cocaine concentrations in mice and rats. Furthermore, h2E2 antagonizes the effect of cocaine in a rat model of relapse. These studies predict h2E2 will be an effective treatment for human cocaine abusers. Our industry collaborator, Catalent Inc., established a Master Cell Bank (MCB) and can produce industrial quantities of purified h2E2 through good manufacturing practices (GMP). The h2E2 from this MCB shows no cross-reactivity in vitro with an extensive panel of human tissues. In animal toxicology studies, h2E2 gave no indications of toxicity at intravenous doses up to 360 mg/kg. These IND- enabling GLP studies predict that h2E2 will be safe for use in humans. During a pre-IND meeting, the FDA agreed that h2E2 could proceed to first-in-human clinical trials to establish safety, and measure the pharmacokinetics, in healthy human volunteers. However, the FDA limited the allowed dose to 40 mg/kg in humans instead of our proposed 120 mg/kg. To proceed to the 120 mg/kg dose in humans, additional studies in animals need to be completed at a 10-fold higher dose (1,200 mg/kg). The FDA also requested studies that maintain high h2E2 levels in animals, requiring repeated dosing at weekly intervals for a month, a duration approximating the predicted exposure time of a single dose in humans. These pre-clinical studies will require a formulation of h2E2 five-fold more concentrated than that required for the human clinical trials. In addition, the FDA requested characterization of peripheral pharmacological interactions of h2E2 and cocaine. Therefore, we will measure the effect of h2E2 on cocaine-induced changes in cardiovascular function in rats. Additionally, we will determine the toxicology and pharmacokinetics of cocaine in the presence and absence of h2E2 using self-administration as a model of chronic cocaine abuse. The successful completion of the studies to assess the safety of h2E2 in the presence of cocaine, and after repeated administrations, will accelerate the clinical development of h2E2 by enabling the required series of Phase Ia and Phase Ib safety clinical trials. This will lead to a Phase II clinical trial to determine whether h2E2 can decrease the probability of relapse in patients with cocaine use disorder. Importantly, efficacy in clinical trials is defined by reductions in cocaine consumption, which is measured by cocaine and/or benzoylecgonine (BE) concentrations in urine. We have recently reported that h2E2 dramatically decreases the urinary excretion of both cocaine and BE in rats. It is proposed to determine the disposition, metabolism, and excretion of cocaine in the presence of h2E2 to understand how cocaine consumption should be appropriately measured. The successful completion of these clinical development milestones will add value to h2E2 and facilitate commercialization.